Developer for developing electrostatic image, image forming apparatus, apparatus unit and facsimile apparatus

Abstract

A developer for developing electrostatic images is constituted by toner containing a binder resin and a charge controller. The charge controller comprises an arylurea compound which is an arylurea having at least one electron-attracting group or electron-donating group, or a polyarylurea including such an arylurea as a recurring unit. The arylurea compound is substantially colorless and can have stable but different levels of triboelectric chargeability depending on the substituents.

What is claimed is: 
     
       1. A developer for developing electrostatic images, comprising: a toner containing a binder resin and a charge controller, said charge controller comprising an arylurea compound which comprises an arylurea having at least one electron-attracting group or electron-donating group, or a polyarylurea including such an arylurea as a recurring unit. 
     
     
       2. The developer according to claim 1, wherein said arylurea has an electron-attracting group. 
     
     
       3. The developer according to claim 2, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR5## wherein Y 1  and Y 2  denote a phenyl or naphthyl group; R 1  and R 2  independently denote a halogen atom, nitro group, sulfonic acid group, carboxyl group, carboxylic acid ester group, cyano group or carbonyl group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  denote a hydrogen atom or C 1  -C 8  hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       4. The developer according to claim 2, which is a monocomponent-type developer comprising the toner. 
     
     
       5. The developer according to claim 4, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR6## wherein Y 1  and Y 2  denote a phenyl or naphthyl group; R 1  and R 2  independently denote a halogen atom, nitro group, sulfonic acid group, carboxyl group, carboxylic acid ester group, cyano group or carbonyl group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  denote a hydrogen atom or C 1  -C 8  hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       6. The developer according to claim 4, wherein said arylurea compound comprises at least one compound selected from the group consisting of: ##STR7## 
     
     
       7. The developer according to claim 4, wherein said arylurea compound is internally added to the toner in a proportion of 0.1-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       8. The developer according to claim 4, wherein said arylurea compound is externally added to the toner in a proportion of 0.01-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       9. The developer according to claim 4, wherein said monocomponent-type developer comprises said toner and silica fine powder having BET specific surface area of at least 30 m 2  /g. 
     
     
       10. The developer according to claim 9, wherein said silica fine powder comprises hydrophobic silica fine powder having a hydrophobicity of 30-80. 
     
     
       11. The developer according to claim 4, wherein said toner contains a colorant. 
     
     
       12. The developer according to claim 4, wherein said toner is a color toner containing a colorant. 
     
     
       13. The developer according to claim 4, wherein said toner is a magnetic toner containing a magnetic material having an average particle size of 0.1-1 micron. 
     
     
       14. The developer according to claim 13, wherein said magnetic material is contained in the magnetic toner in a proportion of 40-150 wt. parts per 100 wt. parts of the binder resin. 
     
     
       15. The developer according to claim 4, wherein said binder resin comprises a styrene-acrylate copolymer. 
     
     
       16. The developer according to claim 4, wherein said binder resin comprises a styrene-methacrylate copolymer. 
     
     
       17. The developer according to claim 4, wherein said binder resin comprises a polyester resin. 
     
     
       18. The developer according to claim 4, wherein microns. 
     
     
       19. The developer according to claim 4, wherein said toner has a weight-average particle size of 4-10 microns and contains 12-60% by number of toner particles having a particle size of 5 microns or smaller, 1-33% by number of toner particles having a particle size of 8-12.7 microns, and 2.0 wt. % or less of toner particles having a particle size of 16 microns or larger. 
     
     
       20. The developer according to claim 4, wherein said monocomponent-type developer contains at least one additive selected from the group consisting of lubricants, abrasives, fluidity-imparting agents, anti-caking agents, and electroconductivity-imparting agents. 
     
     
       21. The developer according to claim 4, wherein said toner contains a waxy substance. 
     
     
       22. The developer according to claim 2, which is a two-component-type developer comprising the toner and a carrier. 
     
     
       23. The developer according to claim 22, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR8## wherein Y 1  and Y 2  denote a phenyl or naphthyl group; R 1  and R 2  independently denote a halogen atom, nitro group, sulfonic acid group, carboxyl group, carboxylic acid ester group, cyano group or carbonyl group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  denote a hydrogen atom or C 1  -C 8  hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       24. The developer according to claim 22, wherein said arylurea compound comprises at least one compound selected from the group consisting of: ##STR9## 
     
     
       25. The developer according to claim 22, wherein said arylurea compound is internally added to the toner in a proportion of 0.1-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       26. The developer according to claim 22, wherein said arylurea compound is externally added to the toner in a proportion of 0.01-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       27. The developer according to claim 22, wherein said monocomponent-type developer comprises said toner and silica fine powder having BET specific surface area of at least 30 m 2  /g. 
     
     
       28. The developer according to claim 27, wherein said silica fine powder comprises hydrophobic silica fine powder having a hydrophobicity of 30-80. 
     
     
       29. The developer according to claim 22, wherein said toner contains a colorant. 
     
     
       30. The developer according to claim 22, wherein said toner is a color toner containing a colorant. 
     
     
       31. The developer according to claim 22, wherein said toner is a magnetic toner containing a magnetic material having an average particle size of 0.1-1 micron. 
     
     
       32. The developer according to claim 31, wherein said magnetic material is contained in the magnetic toner in a proportion of 40-150 wt. parts per 100 wt. parts of the binder resin. 
     
     
       33. The developer according to claim 22, wherein said binder resin comprises a styrene-acrylate copolymer. 
     
     
       34. The developer according to claim 22, wherein said binder resin comprises a styrene-methacrylate copolymer. 
     
     
       35. The developer according to claim 22, wherein said binder resin comprises a polyester resin. 
     
     
       36. The developer according to claim 22, wherein said toner has a weight-average particle size of 3-15 microns. 
     
     
       37. The developer according to claim 22, wherein said toner has a weight-average particle size of 4-10 microns and contains 12-60% by number of toner particles having a particle size of 5 microns or smaller, 1-33% by number of toner particles having a particle size of 8-12.7 microns, and 2.0 wt. % or less of toner particles having a particle size of 16 microns or larger. 
     
     
       38. The developer according to claim 22, wherein said monocomponent-type developer contains at least one additive selected from the group consisting of lubricants, abrasives, fluidity-imparting agents, anti-caking agents, and electroconductivity-imparting agents. 
     
     
       39. The developer according to claim 22, wherein said toner contains a waxy substance. 
     
     
       40. The developer according to claim 1, wherein said arylurea has an electron-donating group. 
     
     
       41. The developer according to claim 40, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR10## wherein Y 1  and Y 2  denote a phenyl group, naphthyl group or anthryl group; R 1  and R 2  independently denote an alkyl group, alkoxy group or amino group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, amino group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  are a hydrogen atom or C 1  -C 8   hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       42. The developer according to claim 40, which is a monocomponent-type developer comprising the toner. 
     
     
       43. The developer according to claim 42, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR11## wherein Y 1  and Y 2  denote a phenyl group, naphthyl group or anthryl group; R 1  and R 2  independently denote an alkyl group, alkoxy group or amino group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, amino group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  are a hydrogen atom or C 1  -C 8  hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       44. The developer according to claim 42, wherein said arylurea compound comprises at least one compound selected from the group consisting of: ##STR12## 
     
     
       45. The developer according to claim 42, wherein said arylurea compound is internally added to the toner in a proportion of 0.1-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       46. The developer according to claim 42, wherein said arylurea compound is externally added to the toner in a proportion of 0.01-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       47. The developer according to claim 42, wherein said monocomponent-type developer comprises said toner and silica fine powder having BET specific surface area of at least 30 m 2  /g. 
     
     
       48. The developer according to claim 47, wherein said silica fine powder comprises hydrophobic silica fine powder having a hydrophobicity of 30-80. 
     
     
       49. The developer according to claim 42, wherein said toner contains a colorant. 
     
     
       50. The developer according to claim 42, wherein said toner is a color toner containing a colorant. 
     
     
       51. The developer according to claim 42, wherein said toner is a magnetic toner containing a magnetic micron. 
     
     
       52. The developer according to claim 51, wherein said magnetic material is contained in the magnetic toner in a proportion of 40-150 wt. parts per 100 wt. parts of the binder resin. 
     
     
       53. The developer according to claim 42, wherein said binder resin comprises a styrene-acrylate copolymer. 
     
     
       54. The developer according to claim 42, wherein said binder resin comprises a styrene-methacrylate copolymer. 
     
     
       55. The developer according to claim 42, wherein said binder resin comprises a polyester resin. 
     
     
       56. The developer according to claim 42, wherein said toner has a weight-average particle size of 3-15 microns. 
     
     
       57. The developer according to claim 42, wherein said toner has a weight-average particle size of 4-10 microns and contains 12-60% by number of toner particles having a particle size of 5 microns or smaller, 1-33% by number of toner particles having a particle size of 8-12.7 microns, and 2.0 wt. % or less of toner particles having a particle size of 16 microns or larger. 
     
     
       58. The developer according to claim 42, wherein said monocomponent-type developer contains at least one additive selected from the group consisting of lubricants, abrasives, fluidity-imparting agents, anti-caking agents, and electroconductivity-imparting agents. 
     
     
       59. The developer according to claim 42, wherein said toner contains a waxy substance. 
     
     
       60. The developer according to claim 40, which is a monocomponent-type developer comprising the toner. 
     
     
       61. The developer according to claim 60, wherein said arylurea comprises an N,N'-bisarylurea derivative represented by the following formula: ##STR13## wherein Y 1  and Y 2  denote a phenyl group, naphthyl group or anthryl group; R 1  and R 2  independently denote an alkyl group, alkoxy group or amino group; R 3  and R 4  denote a hydrogen atom, alkyl group, alkoxy group, amino group, phenyl group capable of having a substituent, or aralkyl group capable of having a substituent; R 5  and R 6  are a hydrogen atom or C 1  -C 8  hydrocarbon group; k and l are 0, 1 or 2 satisfying k+1≧1; and m and n are 1 or 2. 
     
     
       62. The developer according to claim 60, wherein said arylurea compound comprises at least one compound selected from the group consisting of: ##STR14## 
     
     
       63. The developer according to claim 60, wherein said arylurea compound is internally added to the toner in a proportion of 0.1-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       64. The developer according to claim 60, wherein said arylurea compound is externally added to the toner in a proportion of 0.01-10 wt. parts per 100 wt. parts of the binder resin. 
     
     
       65. The developer according to claim 60, wherein said monocomponent-type developer comprises said toner and silica fine powder having BET specific surface area of at least 30 m 2  /g. 
     
     
       66. The developer according to claim 65, wherein said silica fine powder comprises hydrophobic silica fine powder having a hydrophobicity of 30-80. 
     
     
       67. The developer according to claim 60, wherein said toner contains a colorant. 
     
     
       68. The developer according to claim 60, wherein said toner is a color toner containing a colorant. 
     
     
       69. The developer according to claim 60, wherein said toner is a magnetic toner containing a magnetic material having an average particle size of 0.1-1 micron. 
     
     
       70. The developer according to claim 69, wherein said magnetic material is contained in the magnetic toner in a proportion of 40-150 wt. parts per 100 wt. parts of the binder resin. 
     
     
       71. The developer according to claim 60, wherein said binder resin comprises a styrene-acrylate copolymer. 
     
     
       72. The developer according to claim 60, wherein said binder resin comprises a styrene-methacrylate copolymer. 
     
     
       73. The developer according to claim 60, wherein said binder resin comprises a polyester resin. 
     
     
       74. The developer according to claim 60, wherein said toner has a weight-average particle size of 3-15 microns. 
     
     
       75. The developer according to claim 60, wherein said toner has a weight-average particle size of 4-10 microns and contains 12-60% by number of toner particles having a particle size of 5 microns or smaller, 1-33% by number of toner particles having a particle size of 8-12.7 microns, and 2.0 wt. % or less of toner particles having a particle size of 16 microns or larger. 
     
     
       76. The developer according to claim 60, wherein said monocomponent-type developer contains at least one additive selected from the group consisting of lubricants, abrasives, fluidity-imparting agents, anti-caking agents, and electroconductivity-imparting agents. 
     
     
       77. The developer according to claim 70, wherein said toner contains a waxy substance.